Ultra-fine metallic particles have many unique physical and chemical characteristics, which make them ideal materials for a variety of applications, such as electronics, catalysis, metallurgy, and decorations. Compared to the various particle-producing techniques used in the art, the methods based on the chemical precipitation in solutions provide several advantages, e.g., low manufacturing cost and a very good control of the mechanism of metal particles formation. Others in the art have successfully prepared micron and submicron-size metallic powders of Co, Cu, Ni, Pb, and Ag using chemical-based techniques, such as the ones based on the reduction in alcohols or polyols. For example, U.S. Pat. No. 4,539,041 discusses a method for producing micrometer-size metallic particles by using polyols to convert various metallic compounds into metal powders. Nonetheless, these processes require complex equipment and the metallic powders produced are generally more expensive because of the cost of the organic solvents used. The present invention provides a process capable of generating cost effectively highly dispersed crystalline ultra-fine metallic particles in aqueous medium, which are highly desirable in many practical applications, especially in electronics.